By default, Cscope script adds cscope.out from Vim's current directory and from $CSCOPE_DB. However, if you start Vim from say ~/proj/src/a/b/c/, while cscope.out is at ~/proj/src/, that cscope.out won't be loaded automatically.

For ctags, there is a nice trick: with the command :set tags=tags;/ Vim will look for tags file everywhere starting from the current directory up to the root.

This tip provides the same "autoloading" functionality for Cscope. Just add the following to your vimrc: